Ocean observations reap climate science rewards

by CSIRO 
Dr Gary Myers and XBT CSIRO Hobart. Photo by Bruce Miller
Long-term observations of the oceans around Australia are providing the nation’s climate scientists with significant benchmarks for seasonal forecasts and monitoring future climate change.

Initiated near the end of a two-year El Niño event in May 1983, the program involves the deployment of simple ‘expendable instruments’ (XBTs) from commercial shipping that measure temperature and currents to a depth of 800m along routes in the Indian, Pacific and Southern Oceans.

'Today, we have over 60,000 measurements of temperature around Australia that scientists regularly use to assess past long-term trends – test models used to predict future climate or forecast ocean behaviour,' says Dr Meyers, who leads Australia’s Integrated Marine Observing System (IMOS).

'There is so much ocean around Australia influencing our daily weather and longer term climate that it made sense to begin a record from which we could connect ocean change to shifts in rainfall patterns across southern Australia,' says Dr Gary Meyers who, with colleagues at CSIRO, the Bureau of Meteorology (BoM) and the Scripps Institute of Oceanography in the US, established the ocean monitoring system.

'The 1982/83 El Niño came as a big surprise when we saw all kinds of changes around Australia but didn’t understand them. Now these ocean temperature data contribute to the BoM’s routine seasonal climate forecast.'

At 25 years the system stands as one of the longest sustained ocean observing networks in the world, and is a rare long-term record of ocean change in the huge and poorly monitored Southern Hemisphere ocean domain.

Based on the records, CSIRO’s Dr Susan Wijffels and co-authors will publish a landmark paper on the mean currents flowing between Australia and Indonesia in the Journal of Physical Oceanography. These currents form a critical ocean interconnection – the so-called Indonesian Throughflow – in the distribution of heat in the global climate system.

'Today, we have over 60,000 measurements of temperature around Australia that scientists regularly use to assess past long-term trends – test models used to predict future climate or forecast ocean behaviour,' says Dr Meyers, who leads Australia’s Integrated Marine Observing System (IMOS). 'More than 50 scientific publications and books have been published using the Australian data.'

Bureau of Meteorology Seasonal Forecasts (December, 2008) - Temperatures - http://www.bom.gov.au/announcements/media_releases/climate/ahead/20081126T.shtml Rainfall - http://www.bom.gov.au/announcements/media_releases/climate/ahead/20081126R.shtml

IMOS is an Australian Government Initiative through the National Collaborative Research Infrastructure Strategy. CSIRO and the Bureau of Meteorology support IMOS.

The Centre for Australian Weather and Climate Research (CAWCR) click here

The Centre for Australian Weather and Climate Research is a partnership between CSIRO and the Bureau of Meteorology.

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